1. Field of the Invention
The present invention relates to a mobile terminal and, more particularly, to an apparatus and a method for compensating for audio signal distortion in a mobile terminal that automatically control audio signal amplification through feedback of output of an audio amplifier to provide high-quality sounds.
2. Discussion of the Background
Currently, most mobile terminals and mobile appliances use digital audio amplification technology to amplify audio signals. In digital amplification, an analog input audio signal is converted into a digital audio signal, which is then amplified by an audio amplifier and is output as a sequence of pulses to a speaker.
In a mobile terminal or mobile appliance, the gain of an audio amplifier may be set by circuits other than the audio amplifier. Once the amplifier gain is set to a particular value, the audio amplifier may be used at the set gain value irrespective of power levels of input audio signals. If the signal level of an audio signal input to the audio amplifier is too high, the audio amplifier may produce distorted output, which causes the speaker to generate poor sounds. This problem may become severe for a mobile terminal that includes a speaker having a low sound pressure level rating. That is, when the amplifier gain is set to a value greater than a normal gain value for louder sounds, the input of an audio signal that is unexpectedly strong may distort the amplifier output, thereby degrading the audio quality.